Part 2 – Signs: Frequently Asked Questions

Regulatory Signs

Q: Can flags or enhancement panels be used with regulatory signs to enhance their conspicuity in the driver's field of view? I cannot find anything on 'flagging' of regulatory signs in the MUTCD?

A: Yes, flags or enhancement panels can be used with regulatory signs to call additional attention to new or critical signs. A new section has been added to Chapter 2A, Section 2A.15, which identifies 11 specific methods to enhance the conspicuity of standard signs.

Q: I want to put "Buckle Up" safety message stickers/plaques on the back of STOP and YIELD signs in my City. Is this permissible under the MUTCD?

A: No. Section 2B.10 of the MUTCD states that "No items other than inventory stickers, sign installation dates, and bar codes shall be affixed to the fronts of STOP or YIELD signs, and the placement of these items shall be in the border of the sign. No items other than official traffic control signs, inventory stickers, sign installation dates, anti-vandalism stickers, and bar codes shall be mounted on the backs of STOP or YIELD signs. No items other than retroreflective strips (see Section 2A.21) or official traffic control signs shall be mounted on the fronts or backs of STOP or YIELD signs supports." The reason is that "Buckle Up" and other such messages detract from the motorist's recognition of the STOP sign as a stop sign.

Q: Can a R1-5 YIELD HERE TO PEDESTRIANS sign be placed at a pedestrian crosswalk under the Pedestrian Crossing W11-2 warning sign?

A: No, the R1-5 YIELD HERE TO PEDESTRIANS sign is for application with an advance yield line in advance of an unsignalized midblock crosswalk, to decrease the sight obstruction caused by vehicles in adjacent lanes. The R1-5 sign is not for use at the midblock crosswalk itself. The W11-2 Pedestrian Crossing warning sign with downward sloping arrow plaque (W16-7P) used at the crosswalk is a supplement to the advance placement of the Pedestrian Crossing warning sign. An R1-6 In-Street Pedestrian Crossing sign may be installed in the roadway on centerline of the road at such a crosswalk, whether it is at an intersection or midblock, but the R1-6 sign cannot be installed out of the street at the roadside.

Q: Am I required to post ONE-WAY signs in the near right and far left position for divided highways with medians less than 30 feet wide?

A: It depends, as follows: First, where traffic is separated by painted median only (not a physical median), there is no requirement for ONE-WAY signs, as the highway is not a divided highway. Second, where opposing traffic is separated by a physical median, either with or without curbing, less than 30 feet wide, Section 2B.40 requires either the posting of ONE-WAY signs on the near right and far left corners, facing and visible to side road approaches, or the posting of Keep Right signs in the median noses. Based on engineering judgment, both Keep Right signs and ONE-WAY signs can be used at such locations.

Q: Can street name signs be installed on the same post as a STOP sign?

A: Yes, Section 2A.16 of the MUTCD states that "Signs should be individually installed on separate posts or mountings except where a) one sign supplements another, or b) route or directional signs are grouped to clarify information to motorists, or c) regulatory signs that do not conflict with each other are grouped, such as turn prohibition signs posted with one-way signs or a parking regulation sign posted with a speed limit sign, or d) Street name signs are posted with a stop or yield sign."

A: It depends. Maximum statewide speed limits are established by state legislatures according to road class (e.g., Interstate highways) and geographic area (e.g., rural vs. urban areas). The legislated maximum speed limit generally applies to all roads of a particular class throughout the State. This is referred to as a statutory maximum speed limit, which applies "unless otherwise posted" and above which a speed limit cannot be legally posted. For example, the statutory maximum speed limit for rural freeways in a given State might be 65 MPH. No engineering study would be needed to post a 65 MPH speed limit on a rural Interstate highway in that State, and even if an engineering study indicated that 75 MPH might be a more appropriate speed for the conditions, the statutory maximum would prohibit the State from posting any limit higher than 65 MPH. Similarly, statutory maximum limits are often legislated for urban streets within city limits, such as 30 MPH. However, State and local governments typically have the authority to change the limits by establishing speed zones, with posted speed limits lower than the statutory maximum, for highway or street sections where statutory limits do not fit specific road or traffic conditions. An engineering study is required for setting the limit for altered speed zones. The engineering study takes into consideration such factors as operating speeds of free-flowing traffic, crash experience, roadside development, roadway geometry, parking, and pedestrian traffic.

Warning Signs

Q: I have seen applications of "doubled-up" warning signs (posting a second, identical, sign on the left side of the road.) Is this permissible per the requirements of the MUTCD?

A: Yes. "Doubling-up" in this manner is specifically identified in a new section which was added to Chapter 2A, Section 2A.15, which identifies 11 specific methods to enhance the conspicuity of standard signs.

Q: What happened to the "REDUCED SPEED ZONE AHEAD" sign in Chapter 2B?

A: The black on white regulatory sign "REDUCED SPEED ZONE AHEAD" in Chapter 2B of the 2000 MUTCD was deleted in the 2003 edition of the MUTCD and replaced with a new black on yellow diamond Speed Reduction warning sign (W3-5 and W3-5a) in Chapter 2C. This change was made because the message is an advance warning message, warning of a change in the regulatory speed ahead.

Q: The practice of the State DOT in my State recommends that warning signs be placed 500 feet or more back from the point of the hazard (PC of a curve or STOP sign). Why are the recommended advance placement distances in Table 2C-4 typically so much smaller than what my State recommends?

A: The recommended advance placement distance values in Table 2C-4 are a starting point for determining an appropriate advance placement and are not intended to be applied literally. The recommended advance placement distances in Table 2C-4 are 1) stopping sight distance values for the stated speed minus 180 feet for Condition A (for Speed reduction and Lane changing in heavy traffic) and 2) stopping sight distance minus 250 feet for Condition B (decelerating to a stop condition). Table 2C-4 gives distances assuming deceleration at 10 feet per second, for conditions other than decelerating to a stop. For both conditions A and B, warning signs with legends less than 6″ lettering or more than four words need a minimum of an additional 100 feet to be added to the advance placement distance.

Q: Why can't I use engineering judgment to determine if a Horizontal Alignment warning sign is needed?

A: Using engineering judgment to determine if a Horizontal Alignment warning sign is needed has come up short in terms of safety performance. 28% of all highway fatalities occur on horizontal curves. A relationship between curve differential speed (speed on tangent minus recommended curve speed) and safety performance has been established and is the basis for the optional, recommended and mandatory application of Horizontal Alignment warning signs in Table 2C-5.

Q: What happened to the method of using 10 degrees of ball-bank to determine a recommended curve advisory speed?

A: Until recently, the most up-to-date study for design of horizontal curves was conducted in 1947. Based upon new research, the Regulatory and Warning Signs Technical Committee of the National Committee on Uniform Traffic Control Devices recommended that the Ball Bank criteria be increased 2 degrees from 10/12/14 to 12/14/16, which better represents the approximate 8 to 10 mph that the average driver is presently exceeding the existing posted advisory speed for curves. The new values are comparable to the AASHTO 2004 Green Book design values and represent conservative values based on the research. A small adjustment was made in the side friction factors to provide comparable values and the appropriate relationship between lateral acceleration, side friction factors, and ball bank indications based on research by Carlson and Mason, TRB, January 1999. For consistency, it is recommended that the curve advisory speed be determined by either an accelerometer, ball bank determination, or the design formula using the modified side friction factors.

Q: How do I apply the recommended Chevron Spacing Table, Table 2C-6, when I have an Advisory speed which differs from the Curve Radius value?

A: Table 2C-6, Typical Spacing of Chevron Alignment signs on Horizontal Curves, is guidance. The first column for Advisory Speed is applied separately from the 2nd column for Curve Radius as the two may not correspond where superelevation is deficient. Please apply the more restrictive of the first or second column to the values in the 3rd column for chevron sign spacing and you may adjust the sign spacing up or down accordingly based upon engineering judgment, as the table is guidance.

Guide Signs

Q: Can lettering on Street Name signs still be displayed in all upper-case letters?

A: No, lettering for place names and destinations on all guide signs, including Street Name signs, shall be in mixed-case lettering with the first letter in upper-case followed by lower-case letters. This is because mixed-case lettering provides for longer recognition distances than all upper-case lettering when searching for a known word. The combination of ascending and descending strokes of the lower-case letters allows the known word to be recognized earlier. The minimum letter heights for Street Name signs given in Section 2D.43 refer to the height of the initial upper-case letter.

A: The selection of destinations shown on guide sign is determined by the each State and not by the FHWA or the MUTCD. There are two types of destinations: 1) major control cities and 2) supplemental destinations. Recommendations for major control cities are submitted to the American Association of State Highway and Transportation Officials (AASHTO) and approved by AASHTO's Highway Subcommittee on Traffic Engineering. Supplemental destinations are cities other than control cities, or traffic generators. Each State develops selection policies for supplemental destinations. The policy is based on criteria such as interchange spacing, distance of the city or traffic generator from the interchange, population, and annual attendance of a traffic generator. AASHTO has issued guidelines for the selection of control cities and for supplemental guide signs. A copy of the guidelines can be obtained by visiting AASHTO's bookstore located online at https://bookstore.transportation.org.

A: The guide signs for general information, which include the I-series guide signs, reference location signs, and Acknowledgement guide signs, may be found in a new chapter in the 2009 MUTCD, Chapter 2H. Additionally, the General Service Guide signs are now in a new chapter, Chapter 2I.

Other Topics

Q: I would like to rename a highway in honor of a World War I Medal of Honor winner as a lasting memorial for his service to our country. How do I request this?

A: The naming of a highway in memory of someone is a legislative decision that is made by the State or local government in cooperation with the State highway agency. The naming of a street or highway does not require approval or concurrence of the Federal Highway Administration. Once the decision is made to name the highway, then MUTCD Section 2D.53 provides standards and guidance for the proper signing of named highways. In some cases, legislative bodies will designate a highway or portion thereof as a dedication or memorial in honor of a person, without actually changing the name of the highway itself, and will require the posting of a sign to notify the public of the memorial. See Section 2M.10 for proper placement of such memorial signs.

Q: My toll agency is converting to all-electronic toll collection and will no longer accept cash as a payment method; the toll plazas will be removed and open-road tolling instituted. Users registered in a toll-account program with a transponder can pay through a pre-paid account. Other travelers will be sent a bill at the address associated with their license plates and do not need to have registered accounts. Is there any special signing that is needed for this type of cashless toll collection system?

A: This scenario actually simplifies the electronic toll collection signing needs for the traveler. Because the cash payment method is being replaced with an electronic, post-travel bill-by-mail method for general road users, the major signing is essentially the same as it would have been if cash were still accepted because pre-registration in a toll account program is not required for travel. The major guide signing at entrances to the highway would display the black-on-yellow TOLL panel in accordance with Section 2F.13 of the MUTCD. Separate supplemental signing informing road users of the acceptance of a toll-account program and/or the use of the post-travel bill-by-mail for non-registered users may be included near entrances and along the highway. These signs and messages are posted separately from the directional signing for entrances to the highway because they are purely informational in nature and do not restrict or regulate the traffic that is allowed to use the highway. Figure 2F-6 of the MUTCD illustrates the uniform sign sequence and legends. "Bill-by-mail" is the national generic term that has been established for this collection method and is used on any supplemental signs that inform travelers that they will be billed post-travel.

Q: Can a special graphic or name brand be developed and shown on highway signs for the post-travel bill-by-mail toll collection method used on an open-road tolling facility?

A: No. Signing this condition as a toll-payment "system" (such as with a unique pictograph, "branding," or other marketing-type identification) incorrectly implies that pre-registration is required and that others are excluded. Therefore, no special graphic, logo, or name should be included on the major guide signs. Rather, the standard black-on-yellow TOLL panel adjacent to the route marker or highway name is used to convey the fact that a transponder or other pre-registration is not required. Official Ruling No. 2(09)-78 (I), "Signing for Priced Managed Lane without Transponder Requirement," addresses the similar topic of a priced-managed lane without a transponder requirement. If an electronic toll collection transponder can also be used, then this information may be shown on supplemental signs located separately from the directional signs. Figure 2F-6 of the MUTCD illustrates the uniform sign sequence and legends.

Q: What is the status of the Interim Approval for the Clearview™ alternative sign lettering style?

A: Interim Approval 5 was rescinded through a Federal Register notice published January 25, 2016. The Interim Approvals page contains additional information on this topic, including the Federal Register notice, official Memorandum, and Technical Brief.

Q: What happens to existing signs that were installed under Interim Approval 5 and use the Clearview™ lettering style?

A: Existing signs that comply with the Interim Approval may remain as long as they are in serviceable condition. When a sign is no longer serviceable and is replaced, the replacement sign will use the FHWA Standard Alphabets in accordance with the MUTCD.